Clutch



u m y.. vv. T. DUNN W1 CLUTCH Original Filed July l5, 1935 2Sheets-Sheet l W. T. DUNN Sept, 24, 1940.

CLUTCH original Filed July l5. `l935 2 Sheets-Shea t 2 Patented Sept.24, 1940 CLUTCH William T'. Dunn, Detroit, Mich., assignor to ChryslerCorporation, Highland Park, Mich., a corporation of Delaware Originalapplication July 15, 1935, Serial No. 31,320. Divided and thisapplication May 22,

1939, Serial No. 275,038

(Cl. 19Z-105) mi;

, 13 Claims.

This invention relates to power transmission and refers moreparticularly to improvements in speed ratio changing mechanismespecially y adapted for use in driving motor vehicles.

Thisl application is a division of my copending application Serial No.31,320, filed July 15, 1935, now matured as Patent No. 2,182,427.

' One object of my invention is to provide an improved speed ratiochanging mechanism preferably providing an overdrive, or a speed ratiogreater than 1 to 1 between driving and driven shafts in thetransmission of` power from the engine to the vehicle ground wheels.

More particularly, further objects of my invention are to provide amechanism of the character aforesaid having improved characteristics oflong life, quietness of operation, automatic response to the speed ofvehicle travel, and relatively low cost.

26. Another object of my invention is to provide an automatic overdrivemechanism between driving and driven shafts incorporating releasablemeans in the normal Vdirect drive between the shafts and wherein thereleasable the synchronizing action of the members of the automaticclutch; also releasable means for the normal direct drive which may passthrough a movable part of the automatic clutch which con- -fpg trols theoverdrive gear train.

A further object of my invention is to provide an improved arrangementof planetary gearing for the overdrive gear train, this gear train beingcontrolled by an automatic clutch of the centrifugal force operatedtype.

Further features of my invention reside in an improved clutch forcontrolling an overdrive; also an improved clutch having one or morecentrifugal force operated elements adaptf ed to provide a direct driveconnection or a control therefor between the driving and driven shaftsas well as the overdrive connection or a control therefor.

A further object of my invention is to provide an automatic overdriveadapted to func- 45 tion in controllingthe drive with a minimum ofmanual control.

Further objects and advantages of my invention will be more apparentfrom the fol- 50' lowing detailed description of several illustrativeembodiments of my invention, reference being had to the accompanyingdrawings in which:

Fig. 1 is a sectional elevational View of Ymy overdrivinlg' mechanism.

55" Fig. 2 isa transverse sectional elevational 2g means provides atwo-way direct drive prior tov View taken approximately as indicated bythe line 2-2Vin Fig. 1.

Fig. 3 is a, fragmentary sectional elevational view of the parts shownin Fig. 1 but illustratu ing the clutching element in a differentposition of its movement.

Fig. 4 is a detail sectional elevational view taken as indicated bytheline 4 4 of Fig. 1.

Fig. 5 is a view corresponding to Fig. 1 but V illustrating a modifiedform of my overdriving mechanism.

Figs. 6 and 'l are respectively transverse sectional views taken asindicated by the lines B- and l-T of Fig. 5.

Fig. 8 is a side elevational view on a reduced scale illustrating one ofthe clutching elements.

Fig. 9 is a side elevational view of the clutching element illustratedin Fig. 8. l

Referring to the drawings, I have illustrated my overdriving mechanismoperating between a 20 power driving shaft l0 and a driven shaft Il.These two shafts may be arranged anywhere along the line of powertransmission between the usual engine and driving ground wheels of themotor vehicle and inasmuch as such parts 25` are Well known, I have notillustrated them in my drawings. The shaft l0 preferably receives itsdrive from the usual change speed transmission mechanism which may belocated in the casing l2 to the rear of which is located the 30:` casingI3 for housing the overdrive mechanism.

Shaft il] is suitably rotatably journalled,*one bearing therefor beingshown at Ill while shaft` ll is rotatably journalled by bearings l5 andIt, the lusual speedometer drive being taken 35. from shaft H by thegearing Il and I8 in a well known manner.

The driven shaft is provided with an enlarged forward extension coaxialwith the aligned axes of shafts l0 and Il and surrounding the rear endof shaft l0 and while this enlarged projection may be formed integrallywith shaft l I such structure is preferably built up for convenience ofmanufacture as follows: A hub I9 is drivingly secured to shaft Il by thesplines or teeth 451 20, this hub being drivingly engaged as by theteeth 2| with the cylindrical member 22. This latter member has aplurality of circumferentially spaced radial projections 23 adapted torit into rearwardly extending slots 24 of a cylindri- 51ji cal drivingmember 25 formed at the forward end with an internal gear 26 meshingwith a plurality of circumferentially spaced planetary gears 21 mountedon axles 28 connected by the ring-like carriers 29 and 3U. Thesecarriers may 55'? also be connected intermediate a pair of the planetarygears by suitable spacing structures 30' and the carrier 39 is providedwith a rearwardly extending driving member in the form of a cylindricalportion 3| thereof having a plurality of circumferentially spaced slots32 adapted for clutching engagement with the centrifugal force operatedclutching element 33 as will be presently more apparent. The drivingmember 25 transmits a drive from driven shaft II to internal gear 26prior to the overdrive from driving shaft I0 to driven shaft II as willpresently be more apparent. When the overdrive is established, with theengine driving the vehicle, the driving member 25 transmits the drivefrom internal gear 26 to driven shaft II.

The planetary gears 21 also mesh with a sun gear 34 carried by a sleeve35 freely surrounding shaft I4 and non-rotatably secured by teeth 36with a bracket 31 secured to the stationary casing I2.v

The rear end of shaft I0 is provided with sp-lined teeth 38 fordrivingly engaging a cage 39 adapted to carry the clutching element orpawl 33 whereby the latter is rotated with the cage and capable ofradial movement relative thereto in the cage guides 49 and 4I. The pawl33 has an inwardly extending yoked portion 42 surrounding shaft Ill andterminating in a diametrically opposite end portion 43 adapted to housea spring 44 acting between shaft IIJ and an adjustable abutment grooveplug 45 threaded in the outer end of the end portion 43. The spring 44acts to yieldingly urge the pawl 33 into the position illustrated inFig. 2, the shaft I0 serving to limit the movement of the pawl in thisdirection which is the disengaged position of the pawl with respect toits clutching position with one 0f the slots 32.

The pawl 33 is provided with a rearwardly eX- tending projection 46adapted, when the pawl is in its retracted position, to register withone of the circumferentially spaced slots 41 formed in the forwardlyextending face of the cylindrical driven member 22, the arrangementbeing such that when th-e pawl 33 moves outwardly under centrifugalforce, the pawl projection 46 will first be released from the slot 41just prior to movement of the pawl into one of the clutching slots 32 ofthe carrier 30, such intermediate position being illustrated in Fig. 3.

The pawl 33 is adapted for clutching engagement with a slot 32 when therotational speeds of the pawl and slot are substantially synchronizedand in order to facilitate this synchronizang action at the time ofclutching engagement of pawl 33, I preferably provide a releasableclutch between the driving and driven shafts to permit at least acertain amount of relative movement between shafts I and II at the timeof clutching enga-gement. A releasable clutch in the form of a rollerclutch such as is commonly used in free wheeling devices will besatisfactory for this purpose in order to permit the driven shaft tooverrun the driving shaft for synchronizing the clutching element 33with a slot 32. This overrunning clutch comprises an outer cylindricalclutching portion provided by the aforesaid part 22 and an inner cammember 48 drivingly connected to shaft II through the splines 38, theintermediate rollers 49 acting between the clutch portions 22 and 48 andbeing maintained in their properly spaced relationship by a spacer ring50.

In the operation of my driving mechanism, and

with the parts positioned as illustrated in Figs. 1, 2 and 4, it will beapparent that the drive passes from shaft I0 to shaft II as a directtwo-way drive through the intermediary of pawl 33 by reason of theengagement with the pawl projection 46 in slot 41 of driven member 22. Aforward drive supplementing the drive through the pawl is also effectedtending to take at least a part of the forward drive for minimizing thefriction on pawl 33 by reason of the rollers 49 being wedged between thedriving cam member 48 and the outer member 22 driven thereby. It willthus be apparent that this two-way drive will permit a reverse drivebetween shafts I0 and II without any further manual control on theoverrunning clutch and if desired the overrunning clutch may bedispensed with in certain circumstances although it is preferred toincorporate a releasable clutch of some form for operation at leastduring the synchronizing clutching engagement of pawl 33 with slot 32.

When the vehicle is driven at or above a predetermined desired speed forautomatic clutching action of the overdrive, such action beingdetermined by the resistance of spring 44 and the adjustment by thescrew plug 45, the pawl 33 will ily outwardly to release the drivingconnection between pawl portion 4S and slot 41 as shown in Fig. 3. Atthis time the slot 32 is being driven at a slower speed than that of thepawl 33 by reason of the planetary gearing acting as a reduction trainbetween the driven shaft II and the planetary carrier 30 so that bymomentarily slowing down the speed of the driving shaft as by amomentary release of the accelerator pedal, the rotational speeds of thepawl 33 and slot 32 will quickly approach synchronization at which timethe pawl 33 will quickly move outwardly into the slot 32 to provide apositive driving connection between driving shaft I0 and planetarycarrier 3B. The drive will then pass from driving shaft I9 through cage39 and pawl 33 to the carrier 3i), the drive acting through theplanetary gearing to the driven shaft. I I effecting an overdrive in aratio depending on the value of the planetary gear train as will bereadily understood.

When the pawl 33 has moved outwardly sumciently to release its drivingconnection with the driven shaft II, thereby occupying what may betermed an intermediate position just prior to synchronization with therotational speed of the planetary carrier 30 as shown in Fig. 3, theshaft II is not entirely without a drive from the shaft IIJ inasmuch assuch a drive is provided by the rollers 49.

Whenever the motor vehicle is driven at a speed under the critical speedof clutch engagement sufficiently to permit the spring 44 to urge thepawl 33 inwardly, the pawl will release its engagement with slot 32,rollers 49 providing an overrunning action between shaft II and shaftI0, and by increasing the speed of shaft I 0 relative to shaft II thepawl 33 may be synchronized with the speed 0f the driven shaft whereuponthe pawl will move further inwardly to again register the pawlprojection 46 with one of the slots 41 drivingly carried with the drivenshaft to restore the mechanism to the Fig. 1 position.

It will be understood that there is ordinarily a certain amount offriction resisting the movement of pawl 33 from its extreme positions sothat when movement of the pawl takes place further movement in thesamedirection will also readily take place to either completely clutch .the

pawl with a slot 32 on outward movement of the pawl orelse completelyclutch the pawl projection IIB-with one of the slots 41 on inwardmovement of the pawl.

In Figs. 5 to19 I have illustrated a somewhat modied arrangement ofparts primarily consisting in an automatic clutch having a pair ofcentrifugallyi operated Ielements which are adapted for clutchingengagement with slots provided in the cylindrical member of the internalgear to provide the direct two-way drive between the driving and drivenshafts or at least a portion of such drives or where parts of thismechanism are substantially the same in construction and operation asthose aforesaid, I have used similar reference numerals.

In this modified arrangement the driven shaft l l is integrally formedwith the outer cylindrical portion 22i of the overrunning clutch andconnected by members 5| to the cylindrical portion 22a is thecylindrical drivingmember 25EL of the internal gear 26. The cylindricalmember 25EL in this instance is formed with a series ofcircumferentially spaced slots 41a adapted to receive an end portion i3aof a pawl or centrifugal element 33a and 33h. Prior to clutchingmovement of the pawls, each pawl is yieldingly urged by a spring 44a tomaintain the pawl end portions I3a in engagement with one of the slots41a and when the rotational speed of the pawl cage 39a is sufiicient tocause the `pawls to move outwardly against springs 44a, then the ends43a will move inwardly from the slots 4la and the opposite ends of thepawls will then register with the slots 32a of the planetary carrierwhen the planetary carrier and pawls `are substantially synchronized asto their rotation speeds.`

It will be noted from Fig. 5 that the slots 32a and 41aL are spacedaxially with respect to each other in the direction of the axis of thedriving and driven shafts lll and Il, each pawl having its opposite endportions relatively offset in the direction of said 'axis so thatcorresponding end portions of the pawls: will lie in a plane containingthe slo-ts 322L and the slots 41a. Thus, each pawl has an intermediateportion 42a connecting its end portions and this intermediate portionpartially surrounds the driving shaft HJ and also extends longitudinallyof the axis of shaft lll so that the pawls will nest with each other,adjacent end portions of the pawls being in slidable contact as shown inFig. 5.

The operation of the mechanism illustrated in Figs. 5 to 9 issubstantially the same as in the foregoing embodiment of my invention,it being apparent that with the parts positioned, as illustrated in thedrawings, a two-way direct drive will take place between shafts lil andIl through the intermediary of the pawls 33a and 33h supplemented tosome extent by the rollers 49, the slots 32a being freely driven fromthe driven shaft l l;

When the motor vehicle is driven at a predetermined desired speed thecentrifugal force will act to move the pawls outwardly causing the pawlend portions 43a to move inwardly against the associated spring 44.a andthereby disengaging the pawls with the slots 41a to release the two-waydirect drive. At this point in the operation the direct drive betweenshafts IU and ll may, of course, vbe continued through the overrunningclutch rollers 49 although the mechanism is now in condition foreffecting the overdrive upon slowing down the shaft Ill relative toshaft Il to synchronize the rotational speeds of the pawls and slots 32Eat which time the pawls will move further outwardly to clutchinglyengage carrier 30. The drive now continues as an overdrive through theplanetary gearing until such time as the speed of motor vehicle travelis sufciently reduced to cause the springs 44a to move the pawlsinwardly and urge ithe pawl end portions 43a outwardly. As before,

the pawl release from slots 32a will be quickly accompanied bysynchronization of the rotational speeds of the driving and driven.`shafts accompanied by engagement of the pawl end portions 433L in theslots 4la of the driven shaft cylindrical extension 25a.

I do not limit my invention,` in its broader aspects, to the particularcombination and arrangement of parts shown and described forillustrative purposes since various modifications will be; apparentwithin the teachings of my invention as defined in the appended claims.

I claim:

1. In a centrifugally operated clutch, a rotatable shell having a slot,a rotatable cage mounted on a shaft concentric with the shell andcarrying a pawl actuated in one of its directions of movement bycentrifugal force, said pawl having an end portion adapted to engagesaid slot, and a spring acting to move said pawl in opposition to saidcentrifugal force movement, said pawl hav` ing a second portion thereofengaging said shaft for limiting said centrifugal force movement of saidpawl.

2. In a centrifugally operated clutch, a rotatable shell having apawl-receiving slot, a rotatable cage mounted on a shaft concentric withthe shell and carrying a pawl actuated in one of its directions ofmovement by centrifugal force, said pawl having an end portion adaptedto engage said slot, and a spring acting to move said pawl in oppositionto said centrifugal force movement, said pawl having additional portionsthereof respectively engaging said shaft for limiting movement of saidpawl in its said directions of movement. l

3. In a centrifugally operated clutch, a rotatable shell having apawl-receiving slot, a rotatable cage mounted on a shaft concentric withthe shell and carrying a pawl actuated in one of its directions ofmovement by centrifugal force, said shaft having a portion thereofextending into said cage, said pawl having an end portion adapted toengage said slot, and a spring disposed between said pawl and shaft soas to react on said shaft portion and'yieldingly urge movement of saidpawl in opposition to said centrifugal force movement.

4. In a centrifugally operated clutch, a rotatable shell having apawl-receivingslot, a rotatable cage mounted on a shaft concentric'`with the shell and carrying a pawl actuated in one of its directions ofmovement by centrifugal force, said pawl having an end portion adapted tengage said slot, said pawl having a second end portion substantiallydiametrically opposite the slot-engaging end` portion adapted to providea spring seat, said pawl having an intermediate portion deflected atleast partially around said shaft and conn-ecting said end portionstogether, and a spring acting between said shaft and spring seat.

5. In a centrifugally operated clutch, a rotatable shell having apawl-receiving slot, a rotatable cage mounted on a shaft concentric withthe shell and carrying a pawl actuated in one of its directions ofmovement by centrifugal force,

said pawl having an end portion adapted to engage said slot, said pawlhaving a second end portion substantially diametrically opposite theslot-engaging end portion adapted to provide a spring seat, said pawlhaving an intermediate portion surrounding said shaft and connectingsaid end portions together, and a spring acting between said shaft andspring seat for yieldingly/ urging movement of said paWl in oppositionto said centrifugal force movement.

6. In a centrifugally operated clutch, a rotatable shell having apawl-receiving slot, a rotatable cage mounted on a shaft concentric withthe shell and carrying a pawl actuated in one of its directions ofmovement by centrifugal force, said pawl having an end portion adaptedto engage said slot, said pawl having a second end portion substantiallydiametrically opposite said slot-engaging end portion and offsettherefrom in a direction axially of said shaft.

'7. In a centrifugally operated clutch, a rotatable shell having aplurality f pawl-receiving slots, a rotatable cage mounted on a shaftconcentric With the shell and carrying a pawl actuated in one of itsdirections of movement by centrifugal force, said pawl having an endportion adapted to engage one of said slots, said pawl having a secondend portion substantially diametrically opposite said slot-engaging endportion and offset therefrom in a direction axially of said shaft, and asecond pawl carried by said cage, said second pawl having substantiallydiametrically opposite axially offset end portions one of which isadapted for engagement in another of said slots.

8. In a centrifugally operated clutch, a rotatable shell having aplurality of pawl-receiving slots, a rotatable cage mounted on a shaftconcentric vvith the shell and carrying a pawl actuated in one of itsdirections of movement by centrifugal force, said pawl having an endportion adapted to engage one of said slots, said pawl having a secondend portion substantially diametrically opposite said slot-engaging endportion and offset therefrom in a direction axially of said shaft, and asecond pawl carried by said cage, said second pawl having substantiallydiametrlcally opposite axially offset end portions one of which isadapted for engagement in another of said slots, said slot-engaging endportions of said pavvls being disposed for movements in oppositedirections substantially in a plane perpendicular to the axis of saidshaft.

9. In a centrifugally operated clutch, a rotatable shell having apawl-receiving slot, a rotatable cage mounted on a shaft concentric withthe shell and carrying a pawl actuated in one of its directions ofmovement by centrifugal force, said pawl having an end portion adaptedto engage said slot, said pawl having a second end portion substantiallydiametrically opposite said slotengaging end portion and offsettherefrom in a direction axially of said shaft, and a springintermediate said shaft and offset pawl portion.

l0. In a centrifugally operated clutch, a rotatable shell having apawl-receiving slot, a rotatable cage mounted on a shaft concentric withthe shell and carrying a pawl actuated in one of its directions ofmovement by ycentrifugal force, said pawl having an end portion adaptedto engage said slot, said pavvl having a second end portionsubstantially diametrically opposite said slotengaging end -portion andoffset -therefrom in a direction axially of said shaft, and a secondrotatable shell having a slot adapted to receive said second end portionof said pawl.

11. In a centrifugally operated clutch, a rotatable shell having apawl-receiving slot, a rotatable cage mounted on a shaft concentric withthe shell and carrying a pawl actuated in one of its directions ofmovement by centrifugal force, said pawl having an end portion adaptedto engage said slot, said pawl having a second end portion substantiallydiametrically opposite said slot-engaging end portion and offsettherefrom in a direction axially of said shaft, and a second rotatableshell having a slot adapted to receive said second end portion of saidpawl, the slots of said shells being relatively spaced in a directionaxially of said shaft.

12. In a centrifugally operated clutch, a rotatable shell having aplurality of pawl-receiving slots, a rotatable cage mounted on a shaftconcentric With the shell and carrying a pawl actuated in one of itsdirections of movement by centrifugal force, said pawl having an endportion adapted to one of said slots, said pawl having a second endportion substantially diametrically opposite saidslot-engaging endportion and offset therefrom in a direction axially of said shaft, and asecond pawl carried by said cage, said second pawl having substantiallydiametrically opposite axially offset end portions one of which isadapted for engagement in another of said slots, and a second rotatableshell having .a plurality of slots adapted to receive the end portionsof said pavvls Which are substantially diametrically opposite said Islotengaging end portions aforesaid.

13. In a centrifugally operated clutch, a rotatable shell having apawl-receiving slot, a drivetransmitting shaft, a rotatable cage mountedon said shaft concentric with said shell, a pawl carried by said cageand actuated in one of its directions of movement by centrifugal forceinto clutching engagement with said slot when said cage and shell arerotated in synchronism at, or above a predetermined speed, and a springhaving inner and outer end portions, the outer spring portion thrustingon said pawl in opposition to said centrifugal force movement, the innerend portion of said spring being seated directly on said shaft to takethe reaction of the spring.

WILLIAM T. DUNN.

